Electric submersible pumps are often used in the chemical industry to pump large quantities of brine from wells deep in the earth. The brine contains valuable chemicals which are removed and processed. Since the brine is often very highly corrosive, the electric power cables used to deliver power to the submerged pump motors in the wells are subject to deterioration and require replacement at regular intervals.
To resist this corrosion, the electric cables are often highly reinforced and layered. The most common means of constructing such cables is by using one or more layers of extruded lead, fiber reinforced tape, and polymeric layers.
However, use of such heavily leaded and layered cables presents significant problems. One is that the lead layer is difficult to support in the vertical position when gripping is applied to the outer armor layer of the cable. The lead layer is particularly subject to slipping with respect to the armor. In addition, the lead layer is subject to flex creaking induced by bending of the cable. Finally, it is also slowly attacked by the chemicals in the brine.
Examples of typical reinforced power cables are disclosed in the following U.S. Pat. Nos. 2,544,233 to Kennedy; 2,690,984 to Crandall et al; 2,727,087 to Hull; 2,930,837 to Thompson; 3,413,408 to Robinson; 3,566,009 to Lamond et al; 3,832,481 to Boyd et al; 4,284,841 to Tijunelis et al; 4,567,320 to Neuroth et al; and 4,572,926 to Ganssle et al. Also disclosing a reinforced power cable is commonly assigned U.S. patent application Ser. No. 772,413 filed Sept. 4, 1985 for Reinforced Electrical Cable and Method of Forming the Cable in the name of David H. Neuroth, the inventor herein.
Thus, there is a continuing need for improvement in reinforced power cables, especially electric cables used to power submersible pumps in brine wells.